In Bangladesh IDCOL has been implementing biogas programme since 2006 with support from the World Bank, KfW Development Bank and SNV Netherlands Development Organization. Biogas plants not only provide gas for cooking purpose but also produce organic fertilizer for the crops and fish pond. Bio-gas technology is becoming popular in rural Bangladesh in view of escalating costs of fuels as well as soaring prices of chemical fertilizers which our farmers find difficult to buy for their sustainable crop production.
Bio-slurry can be applied in liquid form as ready made manure or with irrigation water. It can be used in semi dried or dried form. Drying makes the transportation easy but the quality of manure is low because of volatilization loss of nitrogen, particularly ammonium. Therefore, the time factor has to be considered while applying the bio-slurry and in this regard, immediate use can be a way of optimizing the results.
For obtaining maximum benefit from organic compost application, the fertilizer should be fully decomposed. Un-decomposed organic manure must be avoided. It is necessary to know whether the compost has attained the stage of maturity before applying it in the field. In practice, mature compost can be identified from its physical appearance of dark brown colour. When pressed between two fingers, matured compost is friable in consistency and can be easily distributed in the field.
There is potential of establishing about 3 million biogas plants in Bangladesh. If the 65 per cent of the potential is tapped then there is a possibility of producing 12 million metric tons of bio-slurry. If a farmer applies 6 tons of dry bio-slurry in crop field, s/he can reduce 60 kg urea, 48 kg TSP and 60 kg MoP fertilizer for selected crop. In Bangladesh, if properly managed, bio-slurry could play a major role in substituting the use of costly chemical fertilizers.
S. Noorus Salam